Since the 1930's, debris basins have been used to catch sediments that otherwise could damage land downstream. The huge basins are designed to catch large amounts of sediment. When they become about 25 percent full, debris basins are cleaned out. Removing the debris is expensive. Each basin holds about 78,480 cubic yards of debris! One reason debris removal is so expensive is that Southern California is running out of places to put the debris. The sediments have to be taken further away for disposal, increasing the cost. Another problem is that some basins have filled up during storms. Generally, however, when debris basins are in the right place, they do a good job of protecting developments downstream from debris flows.